At that moment they were startled by a loud thud in the hall beneath them. The Bible crashed to the floor. Each girl instinctively clapped her hand to her mouth to smother a cry. Then they laughed. "What _ever_ do you suppose it was? Hark--I hear footsteps." Gyp spoke in sepulchral tones. "They're going away," whispered Jerry, relieved. "Goodness, how it frightened me!" Jerry leaned over to lift the poor Bible. From its pages had dropped a long envelope. It lay, white and smooth, the address side upward, on the dusty floor. "Look, Gyp--a _letter_! It must have been in this Bible." Gyp took the envelope gingerly. "It's addressed to father! It's never been opened. It looks as though it had _just_ been written! Jerry--_that's Uncle Peter's handwriting_!" Jerry stared at the envelope--except that the letter had been pressed very flat, it did indeed look as though it had just been written. "Isn't it _creepy_?" Gyp shivered. "Do you believe in ghosts? _Could_ Uncle Peter Westley have come here and written that--just--maybe, _last night_?" It was a horrible thought--Jerry tried not to entertain it. But the wailing wind made it seem possible! "What'll we do with it?" Gyp had laid it on the table. "Let's put it back in the Bible"--that seemed a safe place--"and take it home. Maybe there is an important message in it that someone ought to see! But I wish we'd never come here this afternoon." "And see how dark it is--it's getting late. Let's let these other things go." Jerry's voice, betraying her eagerness to quit the tower room, made Gyp feel creepier than ever. Each took a corner of the ghostly envelope and slipped it between the pages of the Bible. "There--it's safe enough now. We can take turns carrying it." The girls hurriedly donned their outer wraps. Then, without one backward glance, they tiptoed down the narrow stair. But, to their amazement, the panel at the foot of the stair would not budge. Vainly they shoved, and pressed their shoulders against the solid oak. Breathless, Gyp sat down on the Bible. "_What'll_ we do?" "We'll have to shout and bring someone--'cause we can't open the other door." "Then Old Crow will know our secret," wailed Gyp. "But we don't want to stay here all _night_!" Gyp gave one swift, backward glance up the secret stairway to the haunted tower room. "No--no! Well, let's shout together." They shouted and shouted, with all the strength of their young lungs. But Old Crow, who really was Mr. Albert Crowe, for many years janitor of Lincoln School, had gone, ten minutes earlier, in his Sunday best, to attend the annual banquet of the Janitors' Association and his assistant had made his last rounds of the School, so that the shouts of the girls echoed and re-echoed vainly through the deserted halls of Highacres. Jerry leaned, exhausted, against the wall. "I don't believe it's a bit of use--not a soul can hear us."